I've made my own apple molasses before, and it does pick up a bit of a "cooked" flavor from the extended boil (or at least mine did). I tried it as a backsweetener in a batch of cider, but that cooked flavor stuck out like a sore thumb to me. If I were brewing with it, i'd use it in a beer with some roasted/toasted notes to help that flavor blend in. Dubbel sounds interesting. I could see it working in something like a porter or stout as well.
The best place for it is on good vanilla ice cream, though. Second best place is an apple martini.